My earlier invention provided for automatic retraction of a tiller head when a sensor engages a tree trunk, grape stake, or similar thing. I have now found that at times manual control is preferable or even necessary.
One place where automatic by the sensor is inadequate is where one encounters parts of an irrigation system, such as water pipes and risers. The sensor is usually not set to be actuated by such elements; so a manual override by the operator is essential. Another example is that, in hilly terrain, a sensor set properly for the level ground is not properly set for a hillside, where the stakes etc. extend up vertically, not perpendicularly to the ground surface. Going uphill, the sensor will then actuate the retraction too late.
There are also occasions when the sensor is actuated by things that do not actually call for retraction of the tiller,--such as in the spring when mere weeds may actuate the sensor although the tiller should not be retracted. There, disengagement of the sensor is desirable, and manual operation of the retracting mechanism is necessary.
Hence, the present invention enables both manual and automatic operation, with rapid changeover from one to the other.
Another problem has been that in some vineyards or orchards and at certain seasons, grass stems have wound around the tiller tines and have tended to whip against young vine stems. The present invention also addresses this problem and provides means for cutting off such grass stems.
A third problem has been that the tiller tines have heretofore been held down underground during tilling with force that prevents their rising, but at times these tines have, as a result, run into large rocks that tended to damage the tines. This problem is also addressed by the present invention, which enables the operator to place the tines in a free-floating operation when that is desirable.